1. Field
The disclosure relates to a method, system, and article of manufacture for storing parity information for data recovery.
2. Background
Information technology systems, including storage systems, may need protection from site disasters or outages, where outages may be planned or unplanned. Furthermore, information technology systems may require features for data migration, data backup, or data duplication. Implementations for disaster or outage recovery, data migration, data backup, and data duplication may include mirroring or copying of data in storage systems. Such mirroring or copying of data may involve interactions among hosts, storage systems and connecting networking components of the information technology system
Information technology systems may be protected from site outages by copying data from a first site to a second site. The first site may be referred to as an application site, a local site, a primary site or a production site. The second site may be referred to as a recovery site, a remote site, a secondary site or a backup site.
Redundant Array of Independent Disks (RAID) is a mechanism for making disks fault tolerant for disaster recovery in a disk storage system. RAID may use an error correction code, known as parity, to recover from single point of failure errors, i.e., the failure of a single disk. RAID may stripe the data and parity across a plurality of disks to improve the speed of data retrieval and at the same time allow for fault tolerance. There are number of different RAID levels, such as, RAID level 0, 1, 2, 3, 4, 5. For example, RAID level 5 provides data striping at the byte level and also provides stripe error correction information. In RAID level 5, the parity corresponding to data on a plurality of disks may be computed and the parity may be used to recover from a disk failure without losing any data.